Patch antennas that are each formed from a panel of high dielectric constant, low loss dielectric material that is metallized on both sides are well known. More recently there has been described a type of patch antenna that uses what are known as textured dielectric flat panels to improve the performance of the patch antenna. A textured dielectric flat panel for a patch antenna is typically described as a flat panel that comprises three dimensional regions, each region formed from a low loss dielectric, there being at least two dielectric materials having substantially different dielectric constants used to form the patch antenna. The composition of the flat panel may be termed a metamaterial dielectric. Antennas of recent description use two low loss dielectric materials having such dielectric constant values as 100 and 10. The three dimensional regions may be designed using simulation programs that use randomness to generate shapes of the three dimensional regions until certain desired criteria of bandwidth, gain versus frequency, and/or radiation pattern are optimized.
The dielectric material needed to achieve a high dielectric constant, low loss characteristic is typically ceramic. The current technique used to achieve a three dimensional region having a desired shape is to form the shape in enlarged form from a mixture of ceramic particles and a polymer binder, and subsequently fire the shape to burn off the polymer binder and sinter the ceramic particles into a solid ceramic shape. This method limits the choice of materials to those available in fireable powders, for example from LTCC (Low Temperature Co-fireable Ceramic) materials suppliers. The use of a wider variety of materials of varying dielectric constant and lower loss is desirable. The firing step presents significant challenges in maintaining dimensional fidelity to the computer-generated design, because gross shrinkage occurs (25% or more is typical of LTCC), with concomitant warping and cracking problems, particularly for complex, non-solid shapes such as those required here.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.